This invention relates generally to a system and method for dispensing liquid droplets or spray-pattern discharges, and relates more particularly to a system and a method for dispensing droplets or spray-pattern discharges of medicinal liquids into the nasal passage, which system and method provide greater ease of application and privacy for the user, as well as increased mechanical efficiency and improved ability to prevent contamination of the stored medicinal liquids.
Amongst various dispensers for applying medicament, a typical medicament container includes a flexible vial storage portion and a nozzle for dispensing medicament by squeezing the vial between its side walls. Another type of medicament dispenser is an accordion-like or piston-like pump dispenser which is actuated by squeezing the vial between a bottom wall and the nozzle so as to compress the vial in its longitudinal direction, rather than from its sides. An example of the piston-like dispenser which ejects precalibrated dosage of medicament is described in detail in U.S. Pat. No. 5,613,957, which is expressly incorporated herein by reference.
In recent years, pump-type dispensers have received attention for their use in accurately dispensing small doses of medicaments, e.g., for nasal applications. One persistent problem associated with pump-type dispensers for dispensing medicaments is preventing contamination of the medicament which can occur when the medicament that has been exposed to ambient air returns and/or remains in the outlet channel, e.g., within the nozzle. One solution to this problem is to simply add preservatives to the medicament being dispensed, thereby preventing bacterial growth. However, this solution has obvious disadvantages, e.g., added costs and toxicity of the preservatives. In order to prevent bacterial growth in medicament which does not contain preservatives while allowing dispensation of multiple doses of the medicament, the nozzle must prevent any medicament that has been previously exposed to ambient air from being reintroduced, or xe2x80x9csucked back,xe2x80x9d into the outlet channel of the nozzle, i.e., prevent any xe2x80x9cdead volume.xe2x80x9d xe2x80x9cDead volumexe2x80x9d is defined herein as the volume of space within the outlet channel of the pump where medicament can come into contact with the open air and remain. If any residual medicament remains within the dead volume, this residue could serve as a host environment for germ growth.
Another consideration involved in designing pump-type dispensers for medicaments is ensuring accurate dispensation of a predetermined quantity of medicament, e.g., ranging from 5 xcexcl to greater volumes, upon each actuation of the dispenser, irrespective of the orientation of the dispenser or the force applied by the user to the actuation mechanism of the dispenser. While many pump-type dispensers provide an upper limit of the quantity of medicament dispensed upon each actuation of the dispenser, these pumps often dispense varying quantities of medicament as a function of the speed and/or force of actuation of the actuation mechanism of the dispenser. In the case of a pump-type dispenser which generates aerosol or spray-type discharges, not only will the dispensed dose of medicament vary with the speed and/or the force of actuation of the actuation mechanism, but the spray pattern, or the plume, of the dispensed medicament will also vary with the speed and/or the force of actuation.
It should also be noted that persons who suffer from asthmatic or allergic condition routinely need to carry a medicament dispenser with them for emergency situations, but both the existing pressurized medicament dispensers and non-pressurized dispensers have significant drawbacks. The pressurized dispensers are not always ready for use unless they incorporate a heavy glass bottle sustaining vacuum. The non-pressurized devices generally require a particular orientation for dispensing medicament, as well as suffering from a measurable dead volume in the nozzle area.
Yet another problem in designing pump-type dispensers for medicaments is ensuring the ease of applying the medicament. Conventional pump-type dispensers for nasal application, an example of which is shown in FIG. 2, are generally actuated by compression along the length of the dispenser. As shown in FIG. 2, the conventional nasal pump 200 is actuated by pushing down on the syringe arms 203 while supporting the bottom portion 202 with the thumb. The combined actuation motion leads to difficulty in holding the nasal pump in stationary position, and usually results in removal of the nozzle tip 204 from the nostril area. For those users who may have greater than average difficulty with the actuation motion, e.g., elderly patients with arthritis or young children, accidental application of the nasal medicament to the face or into the eye may occur.
Yet another problem associated with the pump-type medicament dispensers is manufacturing complexity: pump-type medicament dispensers are currently made of numerous parts and are highly delicate to assemble. As the number of components increases, the difficulty and cost of mass production increases correspondingly. For example, many of the pump-type dispensers incorporate springs, which pose problems in the manufacturing process because of the springs"" tendency to get intermingled. In addition, very small size of the gaskets and other components make relative movement of the parts difficult. Furthermore, increased number of components also increases the complexity of achieving stability and compatibility of the component materials with the medicament.
One attempt to solve the above-described problems associated with applying medicament from a dispenser is described in my U.S. Pat. No. 5,267,986, which discloses a system including a cartridge for actuating a piston-like or accordion-like vial-dispenser for applying medicament to an eye. The cartridge disclosed in U.S. Pat. No. 5,267,986 includes: a housing for holding the vial-dispenser; a telescoping cylinder for compressing the vial-dispenser in the longitudinal direction to load the vial with medicament; a locking mechanism for locking the telescoping cylinder and the vial-dispenser in the loaded position, against the urging of a spring mechanism of the vial-dispenser; and a trigger mechanism for releasing the telescoping cylinder and the vial-dispenser from the locked position to release the medicament loaded in the dispenser by means of the force of the spring mechanism. In order to obviate the need for a discrete spring element in the pump mechanism of the vial-dispenser, a portion of the vial-dispenser body is made of an elastic material which is compressible and provides spring force. The two-step process in which the cartridge disclosed in U.S. Pat. No. 5,267,986 loads and subsequently releases the medicament from a vial-dispenser defines the basic operation a xe2x80x9creverse pump,xe2x80x9d an example of which is described in U.S. Pat. No. 5,613,957.
The dispensing system disclosed in U.S. Pat. No. 5,267,986 addresses some of the previously-mentioned problems by enabling a user to apply a predetermined dose of medicament independent of the physical force, or speed, applied to the dispensing system by the user: the releasing force or speed of the dispensed medicament is dependent on the integral spring element of the dispensing system. Whereas conventional pump-type dispensers often utilize compression along the longitudinal axis-for release of medicament, the actuation motion of the release mechanism described in U.S. Pat. No. 5,267,986 is preferably achieved in a direction perpendicular to the longitudinal axis of the vial-dispenser to ensure enhanced leverage for the user.
While the dispensing system disclosed in U.S. Pat. No. 5,267,986 addresses some of the previously-mentioned problems, at least one significant problem remains: because elastic materials, particularly elastomeric materials and springs, tend to exhibit hysteresis, spring force decreases if the spring mechanism is kept in the compressed position, i.e., in the loaded, locked position. Although the deformation of spring is generally reversible if the spring is returned to, and maintained in, the unbiased state for some period, some of the deformation becomes irreversible, or experiences xe2x80x9ccreep,xe2x80x9d if the spring is kept in the compressed state beyond a certain threshold period of time, which threshold period varies with the spring material. The amount of loss of spring force is dependent on the tendency of a particular spring material to xe2x80x9ccreep,xe2x80x9d and it is known that metal springs tend to exhibit much less xe2x80x9ccreepxe2x80x9d than plastic springs. The hysteresis of elastic materials used to form the spring mechanism of the pump described in U.S. Pat. 5,613,957 is due to loss of some of the spring property when the spring element remains in the compressed state for an extended, and often unexpected, period of time.
Two examples illustrate the practical implications of the above-mentioned hysteresis problem in connection with the dispensing system disclosed in U.S. Pat. No. 5,267,986. As a first example, a user places the dispensing system in the loaded state but does not actuate the release mechanism for several hours due to an interruption. When the release mechanism is finally actuated, hysteresis of the spring mechanism causes the dosage of released medicament to vary from the dosage calibrated to be released under normal conditions. As a second example, a user places the dispensing system in the loaded state but subsequently forgets about the loaded system; the user does not actuate the release mechanism for several weeks or months. In this situation, not only will the initially-released dosage vary from the calibrated dosage, due to lower actuation speed or force, but subsequently-dispensed dosages will also vary from the calibrated dosage due to a type of permanent deformation, or xe2x80x9ccreep,xe2x80x9d that has occurred, i.e., a permanent change in the actuation stroke. In view of the above-described problem of spring deformation, it would be desirable to have a pump-type medicament-dispensing system which allows the user, by means of a single actuation motion, to load the vial with medicament and subsequently dispense the medicament, without any intervening locking step.
Pump-type dispensers for applying nasal medicaments are faced with yet another problem in providing the users with some level of discreetness: the sight of a conventional pump-type nasal dispenser positioned inside of a nostril is unseemly and often causes embarrassment for the user. Accordingly, it would be desirable to achieve dispensation of nasal medicament without presenting the unsightly appearance of the dispenser positioned inside the nostril.
Still another problem faced by pump-type dispensers is achieving a tight seal of the dispenser after filling it with liquid. The standard approach is to utilize plugs or lids which are formed to mechanically engage the filling opening of a pouch or a container. The main difficulty with this approach is that the allowable mechanical tolerances of the interacting parts of the plug or lid and the opening of the pouch or the container must be extremely small in order to achieve a tight, substantially hermetic seal. Furthermore, even if the interacting parts initially form a tight seal, the portions of the interacting parts which are under pressure tend to experience a xe2x80x9ccreep,xe2x80x9d i.e., deformation of the material, over time. Accordingly, the xe2x80x9ccreepxe2x80x9d phenomenon tends to reduce the tightness of the seal. Thus, there is a need for a mechanical closure system which achieves and maintains a hermetic seal of a pouch or a container over the life of the container.
Accordingly, it is an object of the present invention to provide a pump-type dispenser for dispensing medicament in droplets or spray form, which dispenser facilitates easy application of the medicament while ensuring positional stability of the dispenser during the actuation motion.
It is another object of the present invention to provide a pump-type dispenser for applying medicaments into the nasal passage, which dispenser provides the user with a nasal screen for discreetness.
It is yet another object of the present invention to provide a pump-type dispenser for applying medicaments into the nasal passage, which dispenser provides a guide for aligning the dispenser nozzle with the nasal passage.
It is yet another object of the present invention to provide a pump-type dispenser for applying medicament into the nasal passage, which dispenser ensures a one-way movement of medicament through the nozzle of the dispenser.
It is yet another object of the present invention to provide a pump-type dispenser which has a substantially zero xe2x80x9cdead volumexe2x80x9d in the nozzle portion so that no medicament which has been exposed to ambient air can remain, i.e., the medicament is completely released once it passes through the outlet nozzle, or the combined effect of the surface tensions of the medicament and the surrounding outlet nozzle forces any remaining medicament out of, and away from, the outlet portion.
It is yet another object of the present invention to provide a pump-type dispenser for dispensing nasal medicament, which dispenser minimizes the number of parts for manufacturing.
It is yet another object of the present invention to provide a pump-type dispenser for nasal medicament, which dispenser incorporates a nozzle adapted to generate an aerosol-type discharge by means of elastic, radial deformation along the circumference of the nozzle which simultaneously functions as an integral spring and an elastic valve, while substantially maintaining the physical profile in the direction of the longitudinal axis of the nozzle.
It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser does not require propellants such as CFCs, the release of which is harmful to the ozone layer, or the release pressure of which propellant is temperature dependent, thereby creating variations in dispensed dosages.
It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser emits a predetermined dose of medicament upon each actuation of the dispenser, irrespective of the orientation of the dispenser and the force applied by the user to actuation mechanism.
It is yet another object of the present invention to provide a pump-type dispenser for nasal medicaments, which dispenser emits a predetermined dose of medicament upon each actuation of the dispenser, irrespective of the force applied by the user to the actuation mechanism of the dispenser.
It is a further object of the invention to provide a nasal-medicament dispensing system which can accurately deliver a small, calibrated amount of medicament by means of a single actuation motion which loads the system with medicament and subsequently dispenses the loaded medicament immediately thereafter without any intervening locking step.
It is a further object of the invention to provide a nasal-medicament dispensing system having a single actuation motion for loading and dispensing the medicament, which system incorporates an elastomeric spring element as an integral portion of the body of the dispensing system.
It is a further object of the invention to provide a nasal-medicament dispensing system which includes an actuation mechanism for actuating a vial-dispenser of the type having a spring configuration, e.g., an accordion-like or piston-like vial-dispenser, which actuation mechanism requires minimal force for actuation.
It is a further object of the invention to provide a nasal-medicament dispensing system which substantially eliminates any possibility that spring elements of the dispensing system will exhibit hysteresis of spring characteristics.
It is a further object of the invention to provide a nasal-medicament system in which the actuation motion of the actuation mechanism for dispensing the loaded medicament is in the direction perpendicular to the longitudinal axis of the vial dispenser to ensure enhanced leverage for the user and to avoid the actuation motion being parallel to the compression axis of the spring element.
It is a further object of the invention to provide a method of accurately delivering a small, calibrated amount of medicament by means of a single actuation motion of a medicament-dispensing system which loads the system with medicament and immediately dispenses the loaded medicament thereafter without any intervening locking step.
It is a further object of the invention to provide a method of dispensing a small, calibrated amount of medicament by means of an actuation mechanism for actuating an accordion-like or piston-like vial-dispenser, which actuation motion requires minimal force for actuation.
It is another object of the present invention to provide a mechanical closure system for achieving a tight, substantially hermetic seal of a pouch or a container having an opening.
It is another object of the present invention to provide a method of mechanically sealing a pouch or a container having an opening to achiev e a tight, substantially hermetic seal while simultaneously allowing delivery of gels or suspensions via an outlet nozzle.
It is yet another object of the present invention to provide a mechanical closure system for a pouch or a container having an opening, which mechanical closure system compensates for deformation of the interacting parts of the mechanical closure system and the pouch or the container.
It is yet another object of the present invention to provide a mechanical closure system for achieving a tight, substantially hermetic seal of a pouch or a container having an opening , which system does not require extremely small tolerances for the interacting parts.
It is yet another object of the present invention to provide a method of mechanically sealing an opening of a pouch or a container after having introduced liquid into the container through the opening, which method eliminates the need to provide vacuum conditions for filling the container and, thereby, substantially reduces the cost of the mechanical system for filling the container.
It is yet another object of the present invention to provide a method of mechanically sealing an opening of a pouch or a container, which method involves removably sealing the opening of the pouch or the container in a first configuration, and permanently sealing the opening of the pouch or the container in a second configuration.
It is yet another object of the present invention to provide a system of mechanically sealing an opening of a pouch or a container, which system provides a single-piece sealing element consisting of a mechanical plug detachably coupled to a crimping element via a flange for removably sealing the opening of the pouch or the container, and the system further providing that the crimping element may be detached from the mechanical plug to permanently seal the opening of the pouch or the container.
It is yet another object of the present invention to provide a spray-type dispensing system having a swirling chamber in the region of the nozzle for generating a spray pattern, which system substantially minimizes the head loss in the swirling chamber and in the outflow channels surrounding the swirling chamber.
It is yet another object of the present invention to provide method of generating a spray-type emission from a medicament dispensing system having a swirling chamber in the region of the nozzle for generating a spray pattern, which method substantially minimizes the head loss in the swirling chamber and in the outflow channels surrounding the swirling chamber.
In accordance with the above objects, the present invention provides a pump-type dispenser for dispensing predetermined doses of medicament in droplets or in spray form to the nasal area, which pump-type dispenser incorporates a nasal screen, a pump mechanism, a one-way valve mechanism in the nozzle area, a one-way actuation mechanism and an integral spring element. The nozzle area, which includes the one-way valve mechanism, is adapted to minimize the head loss experienced by the liquid in the nozzle area, thereby achieving more efficient fluid mechanics. The nasal screen not only guides and correctly aligns the dispenser nozzle with the nasal passage, but the screen also serves the important function of allowing the user to discreetly apply the nasal medicament from the dispenser without exposing the nasal area to the public. Furthermore, the one-way valve mechanism in the nozzle area ensures a one-way movement of medicament from the dispenser, thereby preserving substantially perfect sterility of the medicament in the dispenser regardless of the environment surrounding the dispenser, without requiring the use of preservatives.
The one-way actuation mechanism enables the user to sequentially load and dispense the medicament with a single continuous motion of the actuation mechanism upon application of a very small force on the actuation trigger mechanism by the user. The use of the one-way actuation mechanism also enables design simplification by allowing replacement of the traditional metallic spring element with a spring element formed as an integral part of the dispensing system and made from the same elastomeric material as the valve material. The actuation mechanism operates transversely to the length of the dispenser, thereby minimizing the risk that the user will accidentally remove the dispenser nozzle from the nose during use. In addition, the integral spring element formed as a portion of the pump body minimizes the number of component parts for the dispenser, thereby minimizing the manufacturing complexity and the likelihood of mechanical failure during use. Furthermore, the one-way actuation mechanism and the integral spring element provide the dispenser according to the present invention with the unique characteristic of delivering the same precise quantity of medicament at the same actuation force and speed, regardless of the actual force applied to the actuation trigger by the user.
As can be seen from the above, the pump-type dispenser according to the present invention provides a safe, stable and easily operable mechanism for applying medicament to the nasal area. As an additional advantage, the pump-type dispenser according to the present invention for dispensing nasal medicament may be used with substantially all types of liquid formulations, e.g., solutions, suspensions and gels. An exemplary pump mechanism incorporated in the dispenser according to the present invention has: a) a pump body having a front end or tip on the fluid outlet side, the front end comprising an outlet orifice sealed off by an elastic membrane, and continuing backwards through a pump duct with a fluid inlet orifice; and b) a movable piston fitted inside the pump body, the relative displacement of the end of the piston in relation to the pump body between the inlet orifice and a stop position located towards the outlet orifice thus determining the quantity of fluid expelled on displacement, the end of the piston fitting hermetically by slight friction against the duct, the inlet orifice being of a sufficient size for only the preset quantity of fluid or gel to be trapped at the end of the pump duct for its expulsion through the outlet orifice, the pump body and the piston being totally enveloped by an elastic phial, with the exception of the front end of the pump body.
The front end of the pump body, i.e., the tip or xe2x80x9cnose,xe2x80x9d incorporates an outlet orifice preferably in the form of, for example, a cylindrical channel, opening into a pump duct, the latter being, for example, a cylindrical tube, the outlet orifice or channel and pump duct preferably lying in the same general direction. The outlet orifice is preferably a channel advantageously positioned essentially axially along the length of the pump. However, as is clear to those skilled in the field, the channel may be of any shape, e.g., an elbow shape, so as to ensure a projection perpendicular to the axis of the pump.
The elastic membrane may be made of any well-known state-of-the-art elastic material, for example rubber, an elastomer, and preferably thermo-elastic materials such as polyurethane, Adrian(copyright), or those available from AES under the name of VISKAFLEX(copyright), from DUPONT under the name of ALCRYN(copyright) or HYTREL(copyright), from DSM under the name SARLINK(copyright), from SHELL under the name KRATON(copyright), and from Monsanto under the name Santoprene(copyright). The elastic membrane has, at the outlet orifice, a sufficient thickness to form a one-way valve towards the outlet. In other words by working the piston towards the outlet orifice, the force exerted on the piston enables the said valve to open thus enabling the fluid to be expelled. By contrast, after expelling the liquid, if the piston is then drawn back the valve becomes hermetically sealed and, in the pump duct, a reduced pressure or vacuum is created.
The pump duct has a fluid inlet orifice enabling the fluid to fill through the latter. This inlet orifice may be of any shape, rounded, elongated, and may be in the shape of a channel, a slit, a groove, etc.
Similar to a syringe, the pump mechanism according to the present invention incorporates a movable piston fitted inside the pump body; the piston is preferably fitted along the length of the device. xe2x80x9cMovablexe2x80x9d simply indicates that the piston is movable in relation to the body in which it is housed, without prejudicing which element, i.e., the piston or body, moves. This piston can move between a stop position located towards the fluid outlet orifice, and a position beyond the fluid inlet orifice. The stop may be, as in a conventional syringe, the end of the pump duct on the outlet side. However, another stop may be made, if desired, before this end. In the first case, after the fluid is expelled by the relative working of the piston and pump body, the volume of fluid held between the outlet valve and the piston end will be reduced merely to the volume of the evacuation channel. In the second case, the volume of fluid held between the outlet valve and the piston end will include a certain portion of the pump duct in addition to the evacuation channel.
As in a conventional syringe, the end of the piston of the pump according to the present invention fits hermetically by slight friction against the pump cylinder. It will thus be understood that when the piston is drawn in the opposite direction to the outlet orifice, a reduced pressure is created in the pump duct, the said reduced pressure being xe2x80x9cbrokenxe2x80x9d when the end of the piston reaches the level of the fluid inlet orifice. At this point the fluid is sucked into the pump duct which it fills. During the relative displacement of the piston towards the outlet orifice, when the piston goes beyond the inlet orifice, it thus traps in the pump duct a certain volume of fluid. The set volume between this position and the most extreme, stop position of the movable piston corresponds to the preset quantity of fluid which will be expelled by the pump. The compression of the fluid by the piston, the compression being achieved, for example, and preferably with the aid of an elastic, or by pressure with the aid of the thumb on the piston, enables the elastic membrane forming a valve to open and the fluid to be expelled.
The volume of formulation to be delivered by the exemplary phial-pump incorporated in the present invention is small, for example in the order of 5 xcexcl.
As can be seen from the above, the rest position of the pump according to the invention is the position where the piston is at the stop. This is why preferably the pump according to the invention has an elastic means of returning the piston to the stop position. These elastic means are well known to those skilled in the field and are such as a spring, the said spring being fitted inside or outside the pump, along the piston""s axis of displacement; the spring may be made of a metal or plastic material, the nature of the spring being adapted to the fluid contained in the bottle when the said spring is fitted inside the phial in contact with the fluid.
The above-mentioned elastic means may be formed as a part of the envelope of the elastic phial itself, for example, in the form of a concertina, or annular convex part of sufficient thickness to form a mean of return. The envelope is for example at this level integral on one side with the pump body and on the other side with the piston by means of rings with which these element may be fitted. These rings can cooperate with corresponding slots which in this case are made in the envelope. If desired, in order to strengthen the means of return it is possible to use, for example, two return element such as concertinas located more particularly on either side of the retaining ring, integral with the piston a illustrated below. The elastic membrane may be alternatively a separate piece from the elastic phial. However, in preferred conditions of embodiment of the pump mechanism described above, the elastic membrane and the elastic phial form a single piece. The number of pieces of the pump mechanism according to the invention may therefore be remarkably reduced. Indeed, according to the invention, it is possible to have a pump mechanism incorporating just three pieces: a phial made of an elastic material; the pump body and the piston.
The exemplary pump mechanism according to the present invention has a pump body with a frontal ring, fitted close to the fluid outlet. Such a frontal ring enables the elastic phial to be hermetically fixed to the pump body. Such a ring also enables the embodiment of elastic means for returning the piston to the stop position. The pump body may also include a rear ring, which can perform several functions. The rear ring is preferably an incomplete ring, i.e., portions of the ring are cut out.
The above-described piston has the general conformation of an elongated element, corresponding to conventional piston, the elongated element having a plurality of elements, preferably three, in the shape of a ship""s anchor, each thus forming a radial element, at the end of which is an arc-shaped element. The plurality of arcs then forms the incomplete ring referred to above. In such a case, for example, the pump body comprises a cylindrical element, comprising at its front end a ring and at its rear end another cylindrical ring, of larger diameter than the diameter of the arcs described above, the front base of the rear cylindrical ring being cut away so that the above anchors can pass through the base of the cylinder thus enabling, by means of slots corresponding to the above radial elements, and made in the cylinder comprising the pump body, the longitudinal displacement of the piston.
The slots made in the pump body perform two functions: a) on the one hand, they enable the displacement of the piston, by the radial elements sliding along the axis of the slots; and b) on the other hand, the end of the slots on the front side constitutes the fluid inlet orifice enabling the fluid to reach the final pump duct corresponding to the preset volume of fluid to be expelled.
The above-described shape of the piston facilitates the following: a) enable the nozzle portion to be integral with the rear portion of the pump body; b) eliminates the need for the nozzle portion to be snapped into the housing when the piston is moved towards the rear; and c) enables the pump mechanism to be interchangeable within the same housing. The shape of the piston also enables the piston to be actuated through the bellows portion serving as the spring element, without causing or resulting in any motion of the rear vial portion of the pump mechanism. One advantage resulting from the lack of motion involving the rear vial portion is that the pump mechanism does not experience any momentum change as a function of the fluid-content level of the vial, i.e., the pump mechanism exhibits the same momentum characteristics whether the rear vial portion is full or nearly empty, thereby ensuring substantially constant dosage.
In addition to the above-noted advantages, the pump mechanism according to the present invention may also incorporate two O-shaped rings which are secured around the circumference of the pump piston, such that the O-shaped rings provide a fluid-tight seal between the piston and the surrounding sleeve portion of the pump body. The O-shaped rings, which may be made of silicone, polyisoprene, Kraton(trademark), Adrian(trademark), butyl or any rubber-like material, maintain the bellows chamber free of fluid by providing a fluid-tight seal between the pump piston and the surrounding sleeve portion of the pump body. In turn, the absence of fluid in the bellows chamber substantially eliminates the possibility of fluid hindering the elastic deformation of the rear bellows portion.
The dynamics of a pump according to the present invention are summarized below. Let us assume that the equilibrium position is the position in which the piston is at the stop. As is clear for the man skilled in the art, the displacements referred to in the present application are in general relative displacements. Indeed preferably, the piston may be kept stationary and the pump body moved as illustrated below, or the pump body kept stationary and the piston moved to achieve the outlet of the fluid. When the piston draws back, it creates a cavity whose state of pressure is a partial vacuum, indeed the outlet orifice is blocked off by the elastic membrane, preventing the entry of air into the pump. On drawing back further, the piston ends up by reaching the level of a fluid inlet orifice. At this point the pump duct, also referred to as a xe2x80x9cdrop cavityxe2x80x9d or xe2x80x9cdose chamber,xe2x80x9d quickly fills with fluid. The piston can then be pushed back or left to move on to the stop position. When the piston again reaches the level of the fluid inlet orifice, on reaching the end of the latter, it traps a preset volume of fluid. The volume between this extreme position and the stop position of the piston then determines the quantity of fluid expelled. From this moment, ejection of the fluid occurs. As soon as the annular piston lip contacts the compression chamber, the valve opens.
A pump mechanism according to the invention has many advantages which it also confers to an elastic phial fitted with such a pump. The preset volume proposed for the pump may be adjusted by altering both the cross-sectional area of the cavity or pump duct and the length of this cavity by changing the depth of the inlet orifice. The dose is constant and depends neither on gravity nor the activation speed of the pump. It can only depend on the spring effect given to the relative pump body/piston movement, and this for a given viscosity and orifice diameter.
The use of an elastic wall for the envelope makes it possible to achieve in one piece the following functions. First, a one-way valve function is facilitated, enabling operation without drawing in air or the actual substance being delivered; the pump also makes it possible to dispense formulations without preservative which may be used repeatedly without the risk of contamination of the inside of the phial. Second, a phial function is facilitated: the elasticity of the wall in fact enables the wall to cave in gradually as the liquid is evacuated by the pump. Third, the elastic wall functions as an integral spring element.
The injection or filling of the above-described pump mechanism may be associated with a suction which precedes and/or accompanies and/or follows filling so as to eliminate any residual gas in the phial after filling. The dose delivered on each activation of the pump mechanism does not vary, whatever the ambient pressure, because substantially no gas exists inside the system, and the expulsion force applied to the liquid is not dependent on the manual force applied by the user.
The pump-type dispenser mechanism according to the present invention may further incorporate an inner pouch made of an elastic material, e.g., Kraton(trademark), and located within the vial portion. The vial portion, in this case, may be made of a rigid material which substantially eliminates ingress of air into the vial portion. The interior of the inner pouch contains varying volume of air, depending on the amount of liquid contained in the vial portion. The elastic inner pouch is collapsible such that its bottom exterior surface conforms to the liquid level in the vial portion. Accordingly, when the vial portion is completely filled with fluid, the inner pouch is substantially completely collapsed and the volume of the interior is substantially zero. As the liquid in the vial portion is gradually depleted as the result of the pump operation, the inner pouch expands correspondingly, drawn by the suction pressure in the vial portion, thereby substantially eliminating the residual air inside the vial portion, which residual air may adversely affect the operation of the pump. The volume of air in the inner pouch is in turn regulated via air holes.
One embodiment of the pump-type dispenser mechanism according to the present invention may also incorporate a nozzle mechanism for generating an aerosol-type liquid discharge, which nozzle mechanism ensures one-way movement of liquid and also has a substantially zero xe2x80x9cdead volumexe2x80x9d at the tip of the nozzle. The nozzle mechanism according to the present invention is not only suitable for dispensing nasal medicaments, but may be also adapted for use with a variety of types of liquid-dispensing apparatuses, for example, medicament dispensers which channel liquid from a liquid reservoir through the nozzle mechanism by application of pressure via a pump mechanism.
One embodiment of the nozzle mechanism includes a flexible nozzle portion with an outlet and fluid channels, a rigid shaft received within the flexible nozzle portion, and a rigid housing surrounding the flexible nozzle portion and exposing the outlet. The rigid shaft interfaces the outlet to form a second normally-closed, circumferential valve as well as to define a collecting chamber, or a xe2x80x9cswirling chamber,xe2x80x9d for temporarily collecting the liquid which has been channeled from the liquid reservoir, prior to being discharged via the outlet. The outlet has an elastic outer wall, the thickness of which decreases along the elongated axis of symmetry of the outlet from a bottom portion of the outlet toward the tip of the outlet, thereby facilitating one-way movement of liquid through, and out of, the outlet.
In the above-described embodiment of the nozzle mechanism, the fluid channels, which define a portion of a fluid communication path between the liquid reservoir and the collecting chamber, are positioned at various radial edge or circumferential points within the flexible nozzle portion. The radially positioned fluid channels provide uniform pressure with a minimum of xe2x80x9chead lossxe2x80x9d which will be explained later. As a result, the liquid pressure is uniformly applied at the entry point of the swirling chamber once the pressure within the radially positioned fluid channels reach a threshold pressure sufficient to radially deform a first normally-closed, annular or circumferential valve forming a portion of the fluid communication path between the liquid reservoir and the collecting chamber, which first normally-closed valve is described in further detail below. It should be noted that while the first normally-closed valve is positioned annularly, i.e., applies even pressure at all points of the circumference, the fluid channels extend along the longitudinal axis of the flexible nozzle portion and occupy only small sections of the circumference of the second normally-closed valve.
The above-mentioned swirling chamber is used to create a spray pattern for the discharged liquid. The greater pressure differential between the outside and the inside of the pinhole opening of the swirling chamber, the greater the homogeneity and the smaller the spray-particle size. In order to minimize the source of resistance, also referred to as xe2x80x9chead lossxe2x80x9d in fluid mechanics, the length of the fluid channel incorporated in the present invention is minimized, as well as the rate of reduction of the fluid-channel width (if any) and the rate of change of the fluid-channel angle relative to the swirling chamber.
The above-described embodiment of nozzle mechanism according to the present invention may be coupled to a flexible body portion which has a substantially tubular shape and a wall thickness which decreases from the bottom of the body portion toward the flexible nozzle portion, along the elongated axis of symmetry of the body portion. The rigid shaft received within the flexible nozzle portions extends down into the flexible body portion so that a second portion of the rigid shaft interfaces the flexible body portion to form the first normally-closed, radially-positioned valve in the fluid communication path between the liquid reservoir and the collecting chamber. As with the second normally-closed, radially-positioned valve, the first normally-closed, radially-positioned valve is opened when the pressure on the liquid in the fluid communication path reaches a threshold pressure sufficient to radially deform the portion of the flexible body portion forming the first normally-closed, radially-positioned valve.
One advantage of the nozzle mechanism according to the present invention is that the configuration of the outlet portion substantially eliminates the possibility that liquid in the nozzle mechanism will come in contact with ambient air and subsequently return and/or remain in the interior portion of the nozzle mechanism. The nozzle mechanism achieves this result by means of the second normally-closed valve, which facilitates one-way movement of liquid from the nozzle mechanism through the outlet portion during discharge. Due to the second normally-closed valve, the outlet portion has a substantially zero xe2x80x9cdead volumexe2x80x9d, i.e., a space in which liquid that may have been exposed to ambient air can remain.
In addition to the second normally-closed valve, the first normally-closed valve positioned along the fluid communication path between the liquid reservoir and the nozzle mechanism adds further assurances that liquid in the liquid reservoir will not be contaminated by the ambient air and subsequently reintroduced into the nozzle mechanism. Because the first and second normally-closed valves are positioned along the fluid communication path to open asynchronously during fluid communication leading to discharge through the outlet, failure of either one of the valves will not affect the integrity of the nozzle mechanism to prevent contamination of the liquid in the liquid reservoir.
Another advantage of the nozzle mechanism according to the present invention is that the nozzle mechanism experiences substantially no deformation along the direction of the discharge path through the outlet, i.e., the elongated axis of symmetry for the outlet. As a result, the physical profile of the fluid channel, which induces swirling action of the liquid in the collecting chamber of the nozzle mechanism, is maintained during liquid discharge.
Another advantage of the nozzle mechanism according to the present invention is that the number of parts which constitute the nozzle mechanism and, in turn, the dispensing system which includes a pump mechanism in combination with the nozzle mechanism, is significantly reduced in comparison to conventional nozzle mechanisms. The reduced number of parts reduces costs and complexity of assembly.
The pump-type nasal medicament dispenser according to the present invention incorporates an exterior housing and a cartridge positioned within the housing, which cartridge is in turn particularly adapted for actuating an accordion-like or piston-like vial-dispenser mechanism. The vial-dispenser has an accordion-like front bellows portion near the anterior end, a rear vial section or liquid storage chamber at the posterior end, and a rear bellows portion located between the front bellows portion and the rear vial section. A drop cavity or a dosage cavity, which may be located within either the front bellows portion or the rear bellows portion, holds a precalibrated amount of medicament loaded from the liquid storage chamber. In addition, an internal piston mechanism within the vial-dispenser acts in concert with the front and rear bellows portions to expel the medicament contained in the drop cavity.
The cartridge includes a generally elongated body portion which is adapted to receive the vial-dispenser between an anterior wall and a posterior wall of the cartridge. The posterior wall of the cartridge may form a portion of a rear chamber of the cartridge, in which case the rear chamber of the cartridge receives the rear vial section of the vial-dispenser. The anterior wall of the cartridge has an aperture for exposing the nozzle of the vial.
Located on top portion of the cartridge is a trigger mechanism which, when depressed, acts via, and in concert with, a notched lever located in the interior portion of the housing to extend the front bellows portion and compress the rear bellows portion of the vial-dispenser in the longitudinal direction, away from the anterior wall of the cartridge and towards the rear chamber. In the case of the exemplary embodiment of the vial-dispenser described herein, extension of the front bellows portion and compression of the rear bellows portion cause a precalibrated dose of medicament to enter the dosage cavity located in the front of the dispenser, thereby xe2x80x9cloadingxe2x80x9d the dosage cavity.
Continuing with the triggering motion, once the notched lever located in the interior portion of the cartridge has extended the front bellows portion of the vial-dispenser a predetermined distance, the notched lever is disengaged from the front bellows portion by a wedge-shaped arm extending from the rear wall of the cartridge. Upon disengagement from the notched lever, the front bellows portion contracts and the rear bellows portion extends towards the anterior wall of the cartridge. In concert with the movements of the front and rear bellows portions, movement of the internal piston mechanism creates pressure which forces the medicament from the dosage cavity via the anterior nozzle of the vial-dispenser.
The present invention also provides an exemplary embodiment of a mechanical lid or a plug which interacts with an opening of the rear vial section of the vial-dispenser mechanism, as well as with a rigid ring placed inside the vial opening. The mechanical plug is snapped into the vial opening such that the mechanical plug compresses both the outside of the opening and the inner face of the ring placed inside the vial opening, thereby forming a tight seal of the opening.
The opening area of the vial has an annular recess configured to accommodate the rigid ring, where the rigid ring is snapped into the annular recess. After the rigid ring has been snapped into the annular recess of the opening region of the vial, the mechanical plug is snapped both into the rigid ring and around the outside edge of the vial opening so that the vial opening is compressed between the rigid ring and the mechanical plug. The radial edge of the inner face of the mechanical plug is formed as an arch-shaped region which extends around the plug such that the radial edge of the plug is adapted to xe2x80x9chugxe2x80x9d the perimeter of the vial opening. In addition, attached to the inner face of the mechanical plug are two or more legs which extend perpendicular to the lower surface of the mechanical plug. The ends of the legs are hook-shaped to engage the bottom of the rigid ring/radial groove combination. The annular recess and the legs of the mechanical plug facilitate both vertical and radial compression of the opening region of the vial and the rigid ring. In this manner, a tight seal of the vial opening is ensured.
In addition, the outside surface of the opening region of the vial and the interior surface of the annular recess of the mechanical plug each has one or more protrusions, or xe2x80x9cinterferences.xe2x80x9d Once the mechanical plug has been snapped into the vial opening, the resulting compression of the vial material tends to cause displacement, or xe2x80x9ccreep,xe2x80x9d of the compressed material towards areas of lesser compression. The protrusions limit the range of displacement of the compressed vial material, i.e., force the vial material displaced by compression to remain within a defined area, thereby ensuring the tightness of the seal for a prolonged period of time.
The central inner surface of the mechanical plug may be equipped with an extension or a plunger which is adapted to extend into the liquid content of the vial in such a way that the mechanical plug snaps tightly into the vial opening after, and only after, the plunger has displaced the surface level of the liquid up to the upper edge of the vial opening, thereby obviating the need for a vacuum condition normally utilized for an airless filling process. In this manner, the plunger substantially reduces the residual air bubbles which may otherwise remain between the surface of the liquid and the inner surface of the mechanical plug.
As an alternative to the above-described mechanical closure system, the present invention also provides a rigid crimping element detachably coupled via a breakaway flange to a rigid mechanical plug. These elements may be molded as a single piece in order to simplify the manufacturing and assembly process.
The mechanical plug is first inserted into an opening of a neck of the rear vial section of the vial-dispenser mechanism. The mechanical plug and an interior portion of the neck of the vial interact to maintain the mechanical plug within the neck of the vial. However, a predetermined amount of force may dislodge the mechanical plug from the neck of the vial. This detachable engagement between the mechanical plug and the neck of the vial allows the vial to be temporarily sealed for some operations and open for other operations.
In order to permanently and effectively seal the vial, the crimping element is then repositioned relative to, e.g., detached from, the mechanical plug and slipped over the neck of the vial, which action results in compression of the neck of the vial between an inner face of the crimping element and an external face of the mechanical plug, thereby providing a tight, hermetic seal of the vial.
The neck of the vial may be annular and has an inner wall and configured to engage the mechanical plug. A first semicircular protrusion extends substantially around the entire circumference of the inner wall of the neck to engage a first groove on the mechanical plug so that, when the mechanical plug is inserted into the opening of the neck, the first protrusion on the mechanical plug xe2x80x9csnapsxe2x80x9d into the first groove on the mechanical plug. This first step of xe2x80x9csnappingxe2x80x9d the first protrusion into the first groove is reversible so that sterilization of the vial using xcex2 or xcex3 radiation can take place with the first protrusion snapped into the first groove, and the plug can be detached from the neck, i.e., by releasing the first protrusion from the first groove, for subsequent filling of the vial.
A second protrusion extends around an outer wall of the neck of the vial and is configured to engage the crimping element. The second protrusion consists of a semicircular portion extending substantially around the entire circumference of the outer wall of the neck to engage a second groove on the crimping element. When the crimping element is slipped over the neck of the vial, the second protrusion on the neck of the vial xe2x80x9csnapsxe2x80x9d into the second groove on the crimping element to securely couple the crimping element to the neck of the vial. Once the crimping element is xe2x80x9csnappedxe2x80x9d into place, the neck of the vial is then compressed between the crimping element and the mechanical plug to provide a tight seal of the vial. This second step of xe2x80x9csnappingxe2x80x9d the crimping element onto the vial is irreversible, thereby forming a permanent seal.
The interacting surfaces of the crimping element and the neck of the vial have complementary contours which ensure distribution of the compressive force over the entire region of the interacting surfaces when the crimping element is engaging the neck of the vial. In this manner, the present invention substantially eliminates the xe2x80x9ccreepxe2x80x9d phenomenon exhibited by prior art closure mechanisms.
In order to further maintain the crimping element on the neck of the vial, the mechanical plug may further include an overhanging shoulder that extends around the entire circumference of the outer face of the mechanical wall. The crimping element may then have a conical-shaped brim that extends underneath the shoulder of the mechanical plug when the crimping element is slid over the neck of the vial. Thus, any upward movement of the crimping element would be further constricted since the brim of the crimping element would then come into contact with the shoulder of the mechanical plug.
A plunger or extension may also be provided on a bottom surface of the mechanical plug so that, when the mechanical plug is inserted into the neck of the vial, the plunger may extend into a liquid content of the vial in order to raise the surface level of the liquid. Thus, the plunger may substantially reduce the residual air bubbles which may otherwise remain between the surface of the liquid and the inner surface of the mechanical plug.
Yet another exemplary embodiment of a mechanical plug effectively seals the opening of the rear vial section of a vial-dispenser mechanism which incorporates an inner pouch within the rear vial section for minimizing the presence of air inside the rear vial section. A rear portion of the inner pouch has an inverted U shape, and the rear portion radially clasps the opening area of the rear vial section. A radial protrusion of the inner pouch is seated in a complementary recess formed in the opening area of rear vial section, and the rear plug, which also has an inverted U shape, slides over, and radially clasps, the rear portion of the inner pouch and the opening area of the rear vial section to provide a tight seal along both the radial and vertical directions.
Still another exemplary embodiment of a mechanical plug has an annular protrusion which is snap-fitted into a complementary annular recess formed in the opening area of the rear vial section, thereby providing a radial seal along the annular recess. The mechanical plug also has an annular flange which rests against an annular flange of the opening area of the rear vial section. The annular protrusion of the mechanical plug and the annular flange of the opening area act in concert to provide vertical compression of the opening area of the rear vial section.
The pump-type dispenser system according to the present invention for dispensing nasal medicament has several distinct advantages. First, the dispenser system according to the present invention substantially eliminates ingress of air into the pump mechanism, thereby providing not only a sterile environment for the nasal medicament, but also facilitating consistency of the dispensed dosage by minimizing disruption of pump operation caused by air. Second, because the pump-type dispenser according to the present invention is substantially airless, the operation of the pump, as well as the dispensed dosage, is completely unaffected by the orientation of the pump-type dispenser during use. Third, the present invention provides a one-way valve in the nozzle area to further ensure a sterile environment for the nasal medicament inside the dispenser. The valve facilitates only one-way movement of medicament from the interior of the nozzle to the exterior, thereby substantially eliminating the possibility that medicament which has been exposed to ambient air or the exterior of the nozzle may be xe2x80x9csucked backxe2x80x9d into the interior of the nozzle, and, in turn, substantially eliminating the possibility of contamination of the medicament inside the dispenser.
In addition to the above-noted advantages, the pump-type dispenser according to the present invention also provides a mechanism by which aerosol-type discharges of uniform dosage is achieved without any propellant gas such as CFC. This is achieved by utilizing a combination of the above-mentioned airless pump mechanism, a xe2x80x9cone-way actuation release mechanism,xe2x80x9d which facilitate loading and ejection of a uniform dose of medicament with a single actuation motion, and an aerosol-generating nozzle mechanism which achieves a very low xe2x80x9chead lossxe2x80x9d for the fluid discharge.